This invention relates to fasteners for locking the closures of containers, and in particular, containers used for the transportation and storage of ammunition such as shells, missiles, torpedoes, bombs and other more general projectiles.
Usually ammunition of this type is transported or stored in tube-like containers such as are disclosed in U.S. Pat. No. 3,939,967 to Tenney et al and U.S. Pat. No. 4,666,034 to Johnson et al. Such containers comprise a tube or box-like lower portion and a conforming upper portion; the upper and lower portions mate to provide a closed container for the ammunition. In the Tenney et al patent, the upper and lower portions are secured together by a threaded engagement; in the Johnson et al patent, the upper portion is provided with a central threaded rod which can be rotated into a tube attached to the base portion, thereby releasably securing the upper and lower portions. Neither of these patents disclose a means for locking the upper and lower portions of the ammunition container together.
It is desirable to have a means of securing the closure of an ammunition container for two main reasons. Firstly, it is possible that such threaded closures become loose or open when jarred by transportation across rough terrain or by nearby explosions; in such situations a lock would prevent such accidental opening. Secondly, it is necessary to provide a security lock to the closure with which it is possible to detect if the ammunition container has been opened by an unauthorized person.
One technique in current use for detecting whether the closure of a container has been opened, involves the use of a wire passed through two aligned holes, one of which is attached to the closure, the other attached to the container. The ends of the wire are fastened together by means of a metal tag which is crimped to the ends of the wire. If the tag is broken or the wire is severed or missing, one is immediately alerted to the fact that the container has been opened or tampered with. This type of wire seal must be applied to a container using tools, such as pliers, to crimp the tag to the ends of the wire, and in addition, tools, such as metal cutters, are required to remove the wire seal. The use of tools to remove the wire seal is a particular disadvantage for ammunition containers since it is time consuming and leads to an inefficient manner of unloading the ammunition in the field.
Closures for ammunition containers therefore have two conflicting requirements. Firstly, the closures must be made secure to prevent them becoming inadvertantly jarred loose and to prevent tampering with the ammunition. Secondly, the closures must be capable of being opened quickly and easily, to gain swift access to the ammunition under field conditions. The fastener constructed in accordance with this invention seeks to fulfill both of these requirements. It can be applied swiftly and without tools to a container to lock and secure the closure, and when the container is required to be opened, the fastener can be swiftly removed without the aid of tools. In addition, once removed, the fastener cannot be reapplied to the container, its absence thereby indicating that the container has been opened or tampered with.
Further, since the closure is made of plastic, it is useful if the fastener is in a form that it can be easily injection molded, even if some simple subsequent assembly is required.